Tobacco smoke filter

ABSTRACT

A frangible tobacco smoke filter composed of a resilient tubular casing and a unit consisting of interconnected, opposed seals. When the smoker applies pressure to the casing, the unit is broken thereby allowing for passage of the tobacco smoke through a smoke-treating medium contained within the casing.

United States Patent inventor Knud Lindgard 436 lliwuhi Loop, Kailua,Oahu, Hawaii 93734 App]. No. 16,314 Filed Man, 1970 Patented Aug. 3,1971 TOBACCO SMOKE FILTER 7 Claims, 5 Drawing Figs.

U.S. C1 131/266, 131/101, 131/107. 131/267 Int. Cl A24d 1/04, A24f 7/04FieldofSearch 131110.],

[56] References Cited UNITED STATES PATENTS 2,808,057 10/1957 Jaksch 131/10.1 3,122,145 2/1964 St. Louis.. l31/10.1X 3,251,365 5/1966 Keith etal. l3l/l0.7 3,297,038 1/1967 Homburger l3l/10.l X 3,390,686 7/1968 lrbyet a1 131/266 FORElGN PATENTS 1,889,769 3/1964 Germany 131/10.l

Primary Examiner-Samuel Koren Assistant Examiner-G. M. Yahwak ABSTRACT:A frangible tobacco smoke filter composed of a resilient tubular casingand a unit consisting of interconnected, opposed seals. When the smokerapplies pressure to the casing, the unit is broken thereby allowingfor'passage of the tobacco smoke through a smoke-treating mediumcontained within the casing.

PATENTEU AUG 3 1971 TOBACCO SMOKE FILTER This invention relates to theconstruction of a novel frangible filter element designed for containingsmoke-treating media for removing deleterious materials from tobaccosmoke. The filter element is primarily intended for use attached tocigarettes and cigars but may be constructed as a separate cartridge forcigarette or cigar holders and pipes.

The filter consists of one or more frangible containers located withinthe cigarette, cigar or pipe. The filter element is designed to collapseor fracture under intentionally applied pressure by the smoker. Uponfracture or collapse of thecontainer. a smoke-treating medium is thusexposed to the tobacco smoke stream. The tobacco smoke stream is drawnthrough the filter element and is filtered or reacted upon by thesmoketreating media contained therein which may be sorbents, catalystsor any substance specifically designed to remove deleterious substancesfrom the tobacco smoke stream prior to same being inhaled by the smoker.The frangible filter invention is claimed as new because it providesnovel economical means for conserving activated smoke-treating media formaximum efficiency until use. The conservation effect in this caserefers to the sealing effect of the filter element which guards thesmoke-treating medium from saturation or loss of reacting efiiciencystemming from prolonged exposure to the atmosphere or agents containedwithin the tobacco mixture itself. Likewise, the present filterinvention will protect the smoke-treating media against exposure toagents contacted" during the filter incorporation process. The inventionthuswilli enable and improve the utilization of smoke treating mediawhich are otherwise anhydrous, evaporative or deliquescent in naturesuch as bentonite, moisturized charcoal particles, silica gels orliquid-entraining fibrous material.

it is an object of the invention to construct a frangible filter elementthat is economical through usage of simple parts and which lends itselfto automated production to the greatest extent.

Tobacco smoke in general consists of'a gaseous phase in which liquid,semiliquid and solid particles are suspended. The. principle ofcigarette filters is to remove part or all of certain designatedhealth-affecting substances produced by the in-' complete combustion ofthe tobacco mixture. In general, these substances are lumped togetherunder the description as tar and nicotine; but gaseous substances suchas hydrogen sul? fide, carbon monoxide, ketones and other complex, toxicgases of organic origin are also present. The commonly util-' izedfilters of commerce remove from the smoke stream varying portions ofthese substances. Numerous methods and. processes are employed, and theindividual chemical as well as physical properties of the filtermaterials remove more or. less efficiently specifically targetedsubstances. Some of these properties can be defined as active throughsorbtion, anion or cation exchange, diffusion impactive or directcollision of the smoke particles with the filter element constituents.

It is one of the objects of the present invention to augment and topreserve sorbent qualities of sorbent filters. It has been noted thatthe sorbent functions of filter materials such as silica gel, alumina,clays and charcoal, whether pure or chemically treated, largely accountfor the targeted elimination of selected substances from the tobaccosmoke. Such sorbent filters, whether inherently catalytic in nature orcatalyst containing, are, however, only partially effective for severalreasons.

One of the moreimportant reasons is that duringthe filter incorporationand handling the sorbents come in contact with chemicals, vapors andsubstances which partially or completely block the absorbent surfaces ofthe smoke-treating media thereby reducing the sorbent capacity. It is anobject of the present invention to augment the capacity of sorbentfilters by hermetically isolating these until exposed to the tobaccosmoke stream when activated by the user. 7

The addition of various salts, iron oxides or other chemicals ofdeliquescent nature to silica gel, alumina or charcoal can only beeffected at the present within the degree permitted by the presence ofwater vapor in the air or various substances, aromatics, flavors or oilscontained in the tobacco mixture. It is therefore an object of theinvention to permit augmentation or full use of anhydrous, evaporative,or deliquescent agents within the filter element not feasible inpresently marketed filters.

Another object of the present invention is to improve the impactivefiltering effect of granular filters. This effect is achieved through aseparate advantage of the frangible element.

When the seals of the containers fracture, they fragment but do notfully disintegrate. The fracturable portion of the end seals and thesize of resultant fragments can be influenced through a variety ofstructural surface patterns. The result is larger or smaller relativelynarrow surface patterns. The result is larger or smaller relativelynarrow cracks through which the smoke stream is drawn with adifferentialin pressure and with resultant concentration and increase invelocity of smoke particles. This increase in velocity. aids infurthering the inpactive properties of filter materials wherein smokeparticles are retained on granular or pulverulent smoke-treating mediaby surface attraction.

Still another object and advantage of the frangible filter as inventedand described herein is that it'may be manufactured and incorporated incigarettes through the use of automated machinery without majormodifications. To construct a filter capsule with two frangible seals orareas in the shape of discs, or cups, at opposed ends of the frangiblefiler, several methods have been contemplated. One consisted of cuttinglengths of resilient tubing and filling the resultant cylinders withsmoketreating media and then affixing individual seals singularly inboth ends in the form of caps that were subsequently glued or heatsealed. This method in its current state of art proves too slow to beeconomical.

Another method consisted of encapsulating the smoketreatihg media withbrittle plastic or glass by machine processes, as are known inpharmaceutical practices and then coating with resilient plastic. Thecoating was necessary in order to avoid causing injury to the smoker'sfingers when using the element as sharp fragments were produced. Anotherversion considered was that of incorporating several small cylinderseach containinga smoke-treating medium within one resilient casing.The'aforementioned processes did not provide the automated abilityincorporated in the present invention and although feasible they did notrespond to .the requirement for economical manufacture.

The object of the invention then concerns a means for providing afrangible filter element comprising a resilient tube casing with twoindependent frangible seals and overcoming the difiiculty of handlingthe seals singularly and individually. To achieve the desirable effectof handling the end seals as a unit, the two seals'in the form of discsor cups are joined by a connecting bar coaxially situated and placed insuch way as to maintain the end seal discs or cups perpendicular to thewalls of the resilient casing. The connecting bar between the discs orcups is centrally situated for convenience. The connecting bar canequally be transversely extended from the rim of a seal disc to the rimof the opposite seal disc in order to facilitate the utilization ofclayey or spongy filter materials. The proposed difference in connectingthe end discs or cups'shall not be intended to be a deviation from theintent and principle of this invention. The unitized end discs andconnecting bar figuration singularly resembles a spool and shallhereafter be referred to as filter spools. The term filter spool is usedbecause of the visual resemblance; however, utilization as a fixationpoint for threadlike or fibrous material is envisioned. Hollow spheres,throughcutting after manufacture of a rod containing many spools, shallbe considered to constitute the intended disc or rather cup seals withinthe scope of this invention.

The frangible filter asdescribed can be the only filter for use inacigar, pipe or cigarette holder or it can be added toother filters orwith flavor containers so as to'becomesmultipurpose.

Objects and advantages, including novelty, will be apparent to thoseskilled in the art, from reading the specification and claims, inconjunction with the accompanying drawing, in which:

FIG. 1 is a longitudinal cross-sectional view of the frangible tobaccosmoke filter element.

FIG. 2 is a cross-sectional view of the filter element at either end.

FIG. 3 is a longitudinal cross-sectional view of the frangible tobaccosmoke element installed in a cigarette.

FIG. 4 is an exploded view showing the relative position of thefrangible tobacco smoke filter within a cigarette.

FIG. 5 is an elevated enlarged view of the filter spool.

Referring to FIG. 1 the frangible filter element of the inventioncomprises an outer resilient casing 2 which surrounds a smoke-treatingmedium which may be granular as shown but which can also be fibrous orpulverulent. A prerequisite for the smoke-treating medium is adequateporosity necessary to permit passage of smoke stream. The seals 1 and 9at the ends are shown with serrated surfaces; however, any othersuitably patterned surface configuration, for example indented squares,may be utilized. The connecting bar feature 8 between the seals isfurther described herein. Various materials for carrying out theconstruction of the frangible element are apparent. The filter elementcasing 2 may be chosen from suitable materials chosen from the groupsmetal, glass, paper, rubber or plastics. The only prerequisite for thecasing is to be resilient, tasteless and odorless. The material for thefilter spool unit comprising seals 1, 9 and the bar 8 is to be selectedpreferably from the group plastics and in particular a type likeplexiglas which appears to possess the fragmental, friable qualitiesthat are desired. Micas, for an example, may equally be used butplastics are preferred for reason of moldable quality so that the spoolcan be molded in one piece. The feature of friability to the point ofpulverization is not necessarily desired.

In FIG. 2 an end section of the frangible filter element is shown. Thecasing 2 is illustrated with an irregular exterior surface rather thanplain. A foam-textured exterior surface or a surface with elevatedpatterns is desired to provide for a cushion effect to intimatelyaccommodate an intermediate filter wrapper or final wrapper such as thecigarette paper involuting the tobacco charge and the filter components.

FIG. 3 depicts a longitudinal view of a cigarette with the frangibleelement installed. The fibrous plugs 4 and 7 are mainly designed toguard against the smoke-treating medium filter reaching the mouth of thesmoker or contacting the tobacco charge. The fibrous plugs 4 and 7 mayor may not enter into the filtering process as desired. The conventionalmouthpiece wrappers or filter paper wrappers found in cigarettes are notshown in the drawing as they are superfluous to the identification oftheinvention.

FIG. 4 is an exploded view showing the intended position of thefrangible filter element in a smoking article.

FIG. 5 is an elevated view of the filter spool comprising end seal discs1 and 9 and connecting bar 8. The connecting bar 8 is coaxially centeredas illustrated, however, it is the connecting feature that is an objectof the invention and any placement could be made. The connecting bar 8could be placed diagonally between rims of seals 1 and 9 or as many asthree bars could be placed at l20intervals from rim to rim. The form ofa spool as shown would enable utilization of fibrous, threadlikematerials by winding or wrapping around the connecting bar 8. As anexample, such use would include the use of moisturized cotton or acombination of cotton with moist carbon particles. Likewise, it ispossible to manufacture the spool with the bar 8 as a spiral, orangularly, should it be desired. The end discs 1 and 9 of the spool inthe preferred from are concave-concave in both ends; however,concaveconvex and convex-convex are equally acceptable. The purpose ofconcaving or convexing is to impart some structural strength to theseals to allow for sufficient back pressure against the surroundingcasing in order to provide the desired sealing effect.

To produce the filter element presently a continuous tram of linkedfilter spools is manufactured. Each filter spool as linked together is6-9 mm. long and the diameter of the end seals is approximately 6 mm. oras determined by the desired diameter of the cigarette. The linkedspools are approximately 3 mm. apart. The train of linked filter spoolsis then fed upon a continuous U-shaped plastic sheet. The spools arespaced 3 mm. apart and when placed in the bottom of the U-shaped sheetthey form individual compartments into which the filter mixture ismetered. A filling machine, such as a rotary filling apparatus with ametering bar, can fill any number of compartments at one time, the limitbeing only the length of the metering bar and the desired length of thecomposite filter rod to be manufactured. The plastic sheet is thenfolded or roller towards the center and sealed to form a rodconstituting multiple filter elements. Preferably the finished rod isheat sealed at the jointure; however, dependent upon the nature of thesmoke-treating filler, a satisfactory glue or adhesive may be utilized.Another sealing method would be roll wrapping several times using thinplastic sheet or film. Likewise, pressure problems caused by machineproduction may be overcome by using foam-textured plastic material ascasing or as cover for the casing. The resultant filter rod is then cutinto individual lengths representing the frangible filter elements andfed to a filter composite making machine. The sealing effect may befurther augmented by thermoelectric wire cutting of the rod next to theend seal or a heat seal may be added to round the edges at the end sealto provide a firm hold. Lacquers, sealants or hardeners may be added tothe exterior of the casing where warranted. The entire frangible filterconfiguration consisting of the two end plugs and the frangible filterelement is the wrapped in a filter-wrapping machine and subsequentlyincorporated into the cigarette.

In another version of manufacture an individual filter spool is added toa chamber created by the opposed ends of two fibrous plugs, asmoke-treating medium is introduced and the components are involuted inplasticized paper or plastic film wrapper which then creates the casing.Such utilization of the filter spool is but an example which isconsidered to be within the scope of this invention.

Various details of procedure and operation have been set forth above forthe purpose of giving a clear understanding of the invention but are notlimited to the exact details given as it includes modification andchanges coming within the scope of the appended claims.

Having thus described the invention, what I claim as new and desired byLetters Patent is:

l. A tobacco smoke filter element comprising a tubular, resilientcasing, said casing sealed at both ends with frangible, plastic,transversely extending seal discs, said seal discs having the peripheralportions in continuous contact with the interior wall of the casing,said seal discs interspaced to provide a chamber within the casing forcontaining a smoke-treating medium, an axially extending plastic barthrough said chamber and integrally molded with said seal discs to forma single one-piece, spoollike unit, said seal discs to be broken by thesmoker to provide a passage for the tobacco smoke and expose it to asmoke-treating medium when intentionally applying pressure to thecasing.

2. A filter element according to claim 1 wherein the seals are discs,each disc having at lease one curved surface.

3. A filter element according to claim 1 and including upstream anddownstream of said spool unit.

4. A filter element according to claim 1 wherein the casing isconstructed of plastic film.

5. A filter element according to claim 1 wherein the casing isfoam-textured material.

6. A filter element according to claim I wherein the smoketreatingmedium is a sorbent.

7. A filter element according to claim 1 wherein the smoketreatingmedium consists of moisturized carbon particles.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,3,596,665 Dated August 3, 1971 Knud Lindgard Inventor(s) It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

On the cover sheet {72], "436" should read 448 Column 1, line 68,"absorbent" should read adsorbent Column 2 lines 14 and 15, cancel "Theresult is larger or smaller relatively narrow surface patterns"; line19, "inpactive" should read impactive line 28, "filer" should readfilter Column 4, line 14, "roller" should read rolled line 63, after"including" insert fibrous plugs Signed and sealed this 30th day of May1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM uscoMM-oc wan-pan U 5 GOVERNMENT PRHlTlNG OFFICI- Yil'D-IQQ-lli

2. A filter element according to claim 1 wherein the seals are discs,each disc having at lease one curved surface.
 3. A filter elementaccording to claim 1 and including upstream and downstream of said spoolunit.
 4. A filter element according to claim 1 wherein the casing isconstructed of plastic film.
 5. A filter element according to claim 1wherein the casing is foam-textured material.
 6. A filter elementaccording to claim 1 wherein the smoke-treating medium is a sorbent. 7.A filter element according to claim 1 wherein the smoke-treating mediumconsists of moisturized carbon particles.